imx6: clock: Enable External Memory Interface [EIM] clock (eim_slow_clock)

This patch extends the imx6 clock code to enable or disable the EIM
slow clock, which in necessary when one wants to use EIM interface t
o read/write from external memory (e.g. NOR).

Signed-off-by: Lukasz Majewski <l.majewski@majess.pl>
diff --git a/arch/arm/cpu/armv7/mx6/clock.c b/arch/arm/cpu/armv7/mx6/clock.c
index 96fbd81..2995628 100644
--- a/arch/arm/cpu/armv7/mx6/clock.c
+++ b/arch/arm/cpu/armv7/mx6/clock.c
@@ -1384,6 +1384,20 @@
 }
 #endif
 
+#ifndef CONFIG_SYS_NO_FLASH
+void enable_eim_clk(unsigned char enable)
+{
+	u32 reg;
+
+	reg = __raw_readl(&imx_ccm->CCGR6);
+	if (enable)
+		reg |= MXC_CCM_CCGR6_EMI_SLOW_MASK;
+	else
+		reg &= ~MXC_CCM_CCGR6_EMI_SLOW_MASK;
+	__raw_writel(reg, &imx_ccm->CCGR6);
+}
+#endif
+
 /***************************************************/
 
 U_BOOT_CMD(